JP2008089941A - Mask, exposure method and method for manufacturing display element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mask on which a plurality of patterns are arranged so that the plurality of patterns respectively formed in a plurality of pattern regions can satisfactorily be exposed onto a substrate even when the mask is deformed at the time of being mounted on an exposure apparatus. <P>SOLUTION: The mask M has at least first patterns M2, M5 and second patterns M1, M3, M4, M6 to be transferred onto a substrate by exposure, wherein the first patterns M2, M5 requiring higher exposure accuracy than the second patterns M1, M3, M4, M6 are disposed near the center part of the mask M while the second patterns M1, M3, M4, M6 are disposed in a peripheral part than the center part of the mask. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mask for manufacturing a microdevice such as a flat panel display element such as a liquid crystal display element in a lithography process, an exposure method using the mask, and a method for manufacturing a display element using the exposure method. .

When manufacturing a semiconductor device or a liquid crystal display device that is one of the micro devices, a mask (reticle, photomask, etc.) pattern is applied to a large substrate (glass plate) coated with a photoresist or the like via a projection optical system. A projection exposure apparatus that performs projection exposure on a semiconductor wafer or the like is used. By the way, in recent years, a large-sized substrate exceeding 2 m square has been used, and the mask pattern is also enlarged because the mask pattern is exposed on this large-sized substrate at the same magnification. Further, a semiconductor element, a liquid crystal display element, and the like are manufactured through a plurality of exposure processes, and it is necessary to prepare a plurality of masks on which an exposure pattern is formed in each of the plurality of exposure processes, which requires enormous costs. Therefore, a technique has been proposed in which exposure is performed in each of a plurality of exposure processes using a single mask having a plurality of pattern regions used in a plurality of exposure processes such as semiconductor elements (see, for example, Patent Document 1). .
JP 2004-317975 A

  By the way, the mask is usually placed on a mask stage constituting an exposure apparatus. When the mask having a plurality of pattern areas described above is placed on the mask stage and the mask is deformed (bent), the position of the illumination optical system or projection optical system constituting the exposure apparatus in the optical axis direction is the pattern area. There is a problem that the pattern formed in each pattern region cannot be satisfactorily exposed on the substrate.

  An object of the present invention is to arrange a pattern so that a plurality of patterns formed in each of a plurality of pattern areas can be satisfactorily exposed on a substrate even when deformation occurs when mounted on an exposure apparatus. The present invention provides a mask, an exposure method using the mask, and a method for manufacturing a display element using the exposure method.

  The mask according to the present invention is the mask (M) including at least a first pattern (M2, M5) and a second pattern (M1, M3, M4, M6) to be exposed on the substrate (P). The first pattern (M2, M5), which requires higher exposure accuracy than the pattern (M1, M3, M4, M6), is arranged near the center of the mask (M), and the second pattern ( M1, M3, M4, and M6) are arranged at the periphery of the mask (M) rather than the central portion.

  Further, the exposure method of the present invention includes a mask including at least a first pattern (M2, M5) and a second pattern (M1, M3, M4, M6) exposed to different layers on the substrate (P). The exposure of each of the first pattern (M2, M5) and the second pattern (M1, M3, M4, M6) is performed by performing at least one of expansion exposure and pattern synthesis exposure.

  Moreover, the manufacturing method of the display element of this invention is the exposure process (S303) which exposes a predetermined pattern on a board | substrate (P) by the exposure method of this invention, and the said board | substrate exposed by the said exposure process (S303). And a developing step (S304) for developing (P).

  According to the mask of the present invention, the first pattern which requires higher exposure accuracy than the second pattern even when the mask of the present invention is deformed (bent) when mounted on the exposure apparatus. Are arranged in the vicinity of the center of the mask which is not easily affected by the deformation of the mask, and the second pattern is arranged in the periphery of the center of the mask which is easily affected by the deformation of the mask. Therefore, each of the first pattern that requires high exposure accuracy and the second pattern that does not require high exposure accuracy compared to the first pattern can be satisfactorily exposed on the substrate.

  Further, according to the exposure method of the present invention, since exposure is performed using the mask of the present invention having the first pattern and the second pattern, a plurality of masks corresponding to a plurality of layers are manufactured at the time of manufacturing the device. This is unnecessary, and the cost for manufacturing the mask can be reduced. Even when the mask is deformed (bent) when the mask is mounted on the exposure apparatus, each of the first pattern and the second pattern can be satisfactorily exposed on the substrate.

  Further, according to the device manufacturing method of the present invention, since the exposure is performed using the exposure method of the present invention, even when the mask is deformed (bent) when the mask is mounted on the exposure apparatus, the first method is performed. Each of the pattern and the second pattern can be satisfactorily exposed on the substrate, and a good device can be manufactured.

  An exposure apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a schematic configuration of an exposure apparatus according to this embodiment. The exposure apparatus according to this embodiment includes a mask stage MST (see FIG. 4) that supports a mask M on which a pattern is formed, and a plate (substrate) P for forming a display element having an outer diameter larger than 500 mm. A supporting plate stage (not shown), an illumination optical system IL for guiding the illumination light emitted from the light source 1 onto the mask M, and a projection optical system PL for projecting a pattern formed on the mask M onto the plate P It has. Note that the outer diameter being larger than 500 mm means that one side or diagonal of the plate P is larger than 500 mm.

  In the exposure apparatus according to this embodiment, the projection optical system PL includes a plurality (seven) of projection optical units PLa to PLg. The projection optical units PLa, PLc, PLe, and PLg are arranged in the Y direction, and are arranged on the front side in the X direction (scanning direction). Further, the projection optical units PLb, PLd, and PLf are arranged in the Y direction and are arranged on the rear side in the X direction. The projection optical units PLa, PLc, PLe, and PLg and the projection optical units PLb, PLd, and PLf are arranged in a staggered manner so as to face each other in the X direction.

  That is, the exposure apparatus according to this embodiment is a scanning exposure apparatus that performs scanning exposure by moving the mask M and the plate P synchronously with respect to the projection optical system PL constituted by a plurality of projection optical units PLa to PLg. Thus, a so-called multi-lens scan type exposure apparatus is configured. In the following description, the synchronous movement direction of the mask M and the plate P is the X axis direction (scanning direction), the direction orthogonal to the X axis direction in the horizontal plane is the Y axis direction (non-scanning direction), the X axis direction, and the Y axis direction. The direction orthogonal to the Z axis direction. The directions around the X, Y, and Z axes are the θX, θY, and θZ directions.

  As shown in FIG. 1, the exposure apparatus includes a light source 1 composed of, for example, a mercury lamp or an ultrahigh pressure mercury lamp. The illumination light emitted from the light source 1 is condensed at the second focal position of the elliptical mirror 2 via the dichroic mirror 3. The illumination light reflected by the dichroic mirror 3 enters the incident end 50 of the light guide 5 via the relay optical system 4 and exits from the seven exit ends 5a to 5g. Illumination light emitted from the emission end 5a illuminates a predetermined illumination area on the mask M through an illumination optical unit 6a constituted by a condenser lens, an optical integrator, a condenser lens, and the like. Similarly, the illumination light emitted from the emission ends 5b to 5g illuminates a predetermined illumination area on the mask M through illumination optical units 6b to 6g configured by a condenser lens, an optical integrator, a condenser lens, and the like.

  FIG. 2 is a diagram showing the configuration of the mask M. As shown in FIG. As shown in FIG. 2, the mask M has a plurality (six) of pattern regions M1 to M6. An exposure pattern (for example, a gate electrode) corresponding to the first layer of a thin film transistor substrate (hereinafter referred to as a TFT substrate) is formed in the pattern region M1. In the pattern region M2, an exposure pattern (for example, source / drain electrodes) corresponding to the third layer of the TFT substrate is formed. An exposure pattern (for example, a semiconductor layer) corresponding to the second layer of the TFT substrate is formed in the pattern region M3. In the pattern region M4, an exposure pattern (for example, a passivation film) corresponding to the fourth layer of the TFT substrate is formed. In the pattern region M5, an exposure pattern (for example, a pixel electrode) corresponding to the fifth layer of the TFT substrate is formed. An exposure pattern (for example, a black matrix) corresponding to the first layer of the color filter substrate is formed in the pattern region M6.

  That is, the exposure pattern formed in the pattern region M6 is exposed to a color filter substrate (second substrate) different from the TFT substrate on which the exposure patterns formed in the pattern regions M1 to M5 are exposed. The exposure pattern is formed in the pattern region M6 so that the pattern surface of the TFT substrate and the pattern surface of the color filter substrate are combined to face each other. That is, the exposure pattern formed in the pattern area M6 has a positional relationship that is inverted with respect to the exposure patterns formed in the pattern areas M1 to M5.

  An exposure pattern (for example, a pixel electrode) corresponding to the third layer of the TFT substrate and an exposure pattern (for example, a pixel electrode) corresponding to the fifth layer of the TFT substrate are equivalent to an exposure pattern (for example, a pixel electrode) corresponding to the first layer of the TFT substrate. Gate electrode), an exposure pattern (eg, a semiconductor layer) corresponding to the second layer of the TFT substrate, an exposure pattern (eg, a passivation film) corresponding to the fourth layer of the TFT substrate, and an exposure pattern corresponding to the first layer of the color filter substrate. Since higher exposure accuracy than that of the black matrix (for example, black matrix) is required, it is arranged in the pattern areas M2 and M5 located near the center of the mask M. On the other hand, an exposure pattern (for example, a gate electrode) corresponding to the first layer of the TFT substrate, an exposure pattern (for example, a semiconductor layer) corresponding to the second layer of the TFT substrate, and an exposure pattern (for example, the fourth layer of the TFT substrate) For example, an exposure pattern (for example, a black matrix) corresponding to the first layer of the color filter substrate and the passivation film) is disposed in the pattern regions M1, M3, M4, and M6 located at the periphery of the center portion of the mask M.

  Here, the exposure accuracy includes the minimum pattern line width or the pattern position accuracy during exposure. That is, the exposure pattern corresponding to the third layer of the TFT substrate (for example, source / drain electrodes) and the exposure pattern corresponding to the fifth layer of the TFT substrate (for example, pixel electrodes) are the exposure patterns corresponding to the first layer of the TFT substrate. (For example, a gate electrode), an exposure pattern (for example, a semiconductor layer) corresponding to the second layer of the TFT substrate, an exposure pattern (for example, a passivation film) corresponding to the fourth layer of the TFT substrate, and a first layer of the color filter substrate The minimum pattern line width is narrower than the exposure pattern (for example, black matrix), and high positional accuracy is required for the pattern on the plate when exposed on the plate P.

  The pattern arranged in each of the pattern areas M1 to M6 on the mask M is determined based on the amount of deformation caused by being placed on a mask stage MST described later during exposure. That is, when the mask M is deformed by being held on the mask stage MST, a pattern that requires high exposure accuracy in a portion where the flatness of the mask M is high (a portion where the flatness does not exceed a predetermined allowable value). And a pattern that does not require high exposure accuracy is arranged in a portion where the flatness of the mask M is not high (a portion where the flatness exceeds a predetermined allowable value). For example, when the mask M is deformed as shown in FIG. 3, the portion where the flatness of the mask M is high (the portion where the flatness does not exceed a predetermined allowable value) is near the center A of the mask M. Therefore, an exposure pattern (for example, source / drain) corresponding to the third layer of the TFT substrate and an exposure pattern (for example, pixel electrode) corresponding to the fifth layer of the TFT substrate are arranged in the vicinity A of the central portion of the mask M.

  FIG. 4 is a diagram showing the configuration of the mask stage MST on which the mask M is placed. As shown in FIG. 4, the exposure apparatus includes a first dimming member 9a having a longitudinal direction in the non-scanning direction (Y direction) and a guide portion 10a extending in the X direction on the −Y direction side of the mask stage MST. I have. The guide unit 10a is disposed between the illumination optical system IL and the mask M and guides the first dimming member 9a that moves in the X direction.

  In addition, the exposure apparatus includes a second dimming member 9b having a longitudinal direction in the scanning direction (X direction), and a guide portion 10b extending in the Y direction on the −X direction side of the mask stage MST. The guide unit 10b is disposed between the illumination optical system IL and the mask M and guides the second dimming member 9b that moves in the Y direction.

  The first dimming member 9a and the second dimming member 9b are disposed at a predetermined distance from the pattern surface of the mask M, and illumination light is applied to a part of the pattern region formed on the mask M. The light-reducing part in which the amount of light continuously decreases is formed. The first dimming member 9a forms a dimming portion extending in the Y direction (direction intersecting the scanning direction) on the pattern of the mask M, and the second dimming member 9b is in the X direction (scanning direction) on the pattern of the mask M. ) Is formed. At the time of scanning exposure, the first dimming member 9a and the second dimming member 9b are stationary relative to the mask stage MST.

  Mask stage MST has a long stroke in the X direction, which is the scanning direction, and a minute stroke in the Y direction perpendicular to the scanning direction. A mask laser interferometer (not shown) for measuring the position of the mask stage MST in the XY plane is provided, and the mask laser interferometer measures and controls the position of the mask stage MST in real time.

  The illumination light that has passed through the illumination optical unit 6a illuminates a predetermined illumination area of the mask M and enters the projection optical unit PLa. Similarly, the illumination light that has passed through each of the illumination optical units 6b to 6g illuminates a predetermined illumination area of the mask M and enters the projection optical units PLb to PLg, respectively. The projection optical units PLa to PLg project a part of the pattern formed on the mask M onto the plate P as a plurality of individual images.

  Each of the projection optical units PLa to PLg includes a first set of catadioptric optical system that forms an intermediate image of the pattern of the mask M, a field stop disposed at a position where the intermediate image is formed, and a pattern image on the plate P. A second set of catadioptric optical systems, for example, a shift adjustment mechanism comprising two parallel flat glass plates, for example, a rotation adjustment mechanism comprising, for example, a right-angle prism, etc., for example, an image surface comprising a pair of wedge-shaped optical members, etc. A scaling adjustment mechanism including an adjustment mechanism and a lens is provided. The shift adjustment mechanism shifts the pattern image of the mask M formed on the plate P in at least one of the X direction and the Y direction. The rotation adjusting mechanism rotates the image of the pattern of the mask M formed on the plate P around the Z axis. The image plane adjustment mechanism adjusts the image formation position and the inclination of the image plane of each of the projection optical units PLa to PLg. The scaling adjustment mechanism adjusts the magnification (scaling) of the pattern image of the mask M formed on the plate P.

  The plate P is placed on a plate stage (not shown). The plate stage has a long stroke in the X direction, which is the scanning direction, and a long stroke for stepping in the Y direction perpendicular to the scanning direction. Further, the plate stage is configured to be capable of moving a minute amount in the Z direction, θX, θY, and θZ directions. A plate laser interferometer (not shown) for measuring the position of the plate stage in the XY plane with respect to the projection optical system PL is provided. The plate laser interferometer measures and controls the position of the plate stage in real time. The plate laser interferometer uses an X moving mirror 12 extending in the Y direction at the −X side edge of the plate stage, and a Y moving mirror 13 extending in the X direction at the −Y side edge of the plate stage. Measure the position of the plate stage.

  Further, between the projection optical system PL and the plate P, two light shielding members 9c that shield unnecessary illumination light when a pattern formed on the mask M is transferred onto the plate P are arranged. The two light shielding members 9c are configured to be movable in the Y direction. By moving the two light shielding members 9c in the Y direction, illumination light via at least one of the projection optical modules PLa to PLg is placed on the plate P. Shade out to prevent it from reaching.

  Also, between the −X side projection optical modules PLa, PLc, PLe, and PLg and the + X side projection optical modules PLb, PLd, and PLf, the Z axis of the pattern surface of the mask M and the exposed surface of the plate P An autofocus detection system 15 for detecting a position in the direction is provided.

Next, an exposure method using the exposure apparatus according to this embodiment will be described with reference to the flowchart shown in FIG. In the following description, the first region I ₁ (see FIG. 6), the second region I ₂ (see FIG. 7), the second region where the pattern formed in the pattern region M1 of the mask M is synthesized on the plate P is screened. Divided into three areas I ₃ (see FIG. 8) and fourth area I ₄ (see FIG. 9), and the first area I ₁ to the fourth area I ₄ are combined in a common area (joint portion) on the plate P. Next, an exposure method in which the first region I ₁ to the fourth region I ₄ are screen-synthesized by forming a light-reducing portion with a light-reducing member and transferred onto the plate P will be described.

First, preparation for transferring and exposing the first region I ₁ (see FIG. 6) of the pattern region M1 onto the plate P is performed. FIG. 6 is a diagram showing the first region I ₁ of the mask M. As shown in FIG. The first region I ₁ has a common region I ₁₂ with a second region I ₂ (see FIG. 7) described later and a common region I ₁₃ with a third region I ₃ (see FIG. 8) described later. The common region I ₁₂ extending in the Y direction is a region that becomes a joint when the pattern formed in the first region I ₁ and the second region I ₂ is transferred and exposed on the plate P. ₁₂ and a pattern formed in a common area I ₂₁ (see FIG. 7) of the second area I ₂ described later are superimposed on the plate P and transferred and exposed. Similarly, the common region I ₁₃ extending in the X direction is a region that becomes a joint when the pattern formed in the first region I ₁ and the third region I ₃ is transferred and exposed on the plate P. A pattern formed in the common region I ₁₃ and a common region I ₃₁ (see FIG. 8) of a third region I ₃ to be described later is superimposed and exposed on the plate P.

First, in order to transfer exposure a pattern formed in the first region I ₁ on the plate P, as shown in FIG. 6, -X common area I ₁₂ extending a first extinction member 9a in the Y direction disposed at a position half of the direction side is blocked, half of the + Y direction side of the common region I ₁₃ extending a second extinction member 9b in the X direction is arranged at a position where light is blocked. Further, when the patterns formed in the first region I ₁ , the second region I ₂ and the third region I ₃ are sequentially scanned and exposed, the integrated light amount in the common regions I ₁₂ and I ₁₃ becomes the common region I _12. , I ₁₃ , the first dimming member 9 a and the second dimming member 9 b are defocused with respect to the pattern surface of the mask M, that is, separated by a predetermined distance so as to be substantially the same as the light amount in the region other than I ₁₃ . Place in position.

Furthermore, in order to transfer exposure a pattern formed in the first region I ₁ on the plate P, and the light shielding so as not to reach the illumination light for illuminating the first region I ₁ other than the region on the plate P. For example if you illuminate the first area I ₁ by illumination light portion passing through the illumination light and an illumination optical unit 6e through the illumination optical unit 6 a to 6 d, the illumination optical unit 6f, opening and closing a shutter (not shown) in 6g Is closed to block the illumination light passing through the illumination optical units 6f and 6g. Further, in order to shield the illuminating light that does not illuminate the first region I ₁ of the illumination light passing through the illumination optical unit 6e, it illuminates the first region I ₁ of the illumination light passing through the projection optical units PLe The light shielding member 9c is moved and arranged in the Y direction at a position where light that is not illuminated is shielded (step S10).

Next, the first dimming member 9a and the second dimming member 9b are stationary relative to the mask stage MST, and the mask stage MST and the plate stage are relative to the illumination optical system IL and the projection optical system PL. manner by scanning movement, transferring exposing a pattern formed in the first region I ₁ on the plate P (step S11).

Next, preparation for transferring and exposing the pattern formed in the second region I ₂ (see FIG. 7) of the pattern region M1 onto the plate P is performed. Figure 7 is a diagram showing a second region I ₂ of the mask M. The second region I ₂ has a common region I ₂₁ with the first region I ₁ and a common region I ₂₄ with the fourth region I ₄ (see FIG. 9). The common region I ₂₁ extending in the Y direction is a region that becomes a joint when the pattern formed in the first region I ₁ and the second region I ₂ is transferred and exposed on the plate P. _The pattern formed in the common area I ₁₂ of the first area I ₁ and the first area I ₁ is transferred and exposed while being superimposed on the plate P. Similarly, the common region I ₂₄ extending in the X direction is a region that becomes a joint when the pattern formed in the second region I ₂ and the fourth region I ₄ is transferred and exposed on the plate P. A pattern formed in the common area I ₂₄ and a common area I ₄₂ (see FIG. 9) of a fourth pattern area I ₄ to be described later is superimposed and exposed on the plate P.

First, in order to transfer exposure a pattern formed in the second region I ₂ on the plate P, as shown in FIG. 7, + X direction of the common region I ₂₁ extending a first extinction member 9a in the Y direction disposed at a position half side is shielded, the second dimming member 9b is half the + Y direction side of the common region I ₂₄ extending in the X direction to place at a position where light is blocked. Further, when it is scanned and exposed, the common area _{I 21,} the integrated amount of light at _{I 24} is the common area _{I 21,} such that the light quantity substantially equal in the region other than the _{I 24,} first dimming member 9a and the second The light reducing member 9b is disposed at a position defocused with respect to the pattern surface of the mask M, that is, at a position separated by a predetermined distance.

Furthermore, in order to transfer exposure a pattern formed in the second region I ₂ on the plate P, and the light shielding so as not to reach the illumination light for illuminating the second region I ₂ other than the region on the plate P (step S12). Since the specific operation for light shielding is the same as the operation in step S10, detailed description thereof is omitted.

Next, the mask stage MST is moved to a predetermined position, that is, a scanning start position for scanning exposure of the pattern formed in the second region I ₂ on the plate P, and is formed in the second region I _2. The exposed pattern is transferred and exposed on the plate P (step S13). The specific transfer exposure operation is the same as the operation in step S11, and thus detailed description thereof is omitted.

Next, preparation for transferring and exposing the pattern formed in the third region I ₃ (see FIG. 8) of the pattern region M1 onto the plate P is performed. FIG. 8 is a diagram showing the third region I ₃ of the mask M. As shown in FIG. The third region I ₃ has a common region I ₃₁ with the first region I ₁ and a common region I ₃₄ with the fourth region I ₄ (see FIG. 9). The common region I ₃₁ extending in the X direction is a region that becomes a joint when the pattern formed in the first region I ₁ and the third region I ₃ is transferred and exposed on the plate P. ₃₁ and the pattern formed in the common area I ₁₃ of the first area I ₁ are superimposed on the plate P and transferred and exposed. Similarly, the common region I ₃₄ extending in the Y direction is a region that becomes a joint when the pattern formed in the third region I ₃ and the fourth region I ₄ is transferred and exposed on the plate P. A pattern formed in the common area I ₃₄ and a common area I ₄₃ (see FIG. 9) of a fourth area I ₄ to be described later is superimposed and exposed on the plate P.

First, in order to transfer exposure a pattern formed on the third region I ₃ on the plate P, as shown in FIG. 8, -X common area I ₃₄ extending a first extinction member 9a in the Y direction disposed at a position half of the direction side is blocked, half of the -Y direction side of the common region I ₃₁ extending a second extinction member 9b in the X direction is arranged at a position where light is blocked. Further, when it is scanned and exposed, the common area _{I 31, I} accumulated light amount of _34, the common area _{I 31,} such that the light quantity substantially equal in the region other than the _{I 34,} first dimming member 9a and the second The light reducing member 9b is disposed at a position defocused with respect to the pattern surface of the mask M, that is, at a position separated by a predetermined distance.

Furthermore, in order to transfer exposure a pattern formed on the third region I ₃ on the plate P, and the light shielding so as not to reach the illumination light to illuminate an area other than the third area I ₃ on the plate P (step S14). Since the specific operation for light shielding is the same as the operation in step S10, detailed description thereof is omitted.

Next, place the mask stage MST and the plate stage, i.e., is moved to the scanning start position for scanning exposure pattern is formed on the third region I ₃ on the plate P, the third mask M the pattern formed in the region I ₃ is transferred and exposed onto the plate P (step S15). The specific transfer exposure operation is the same as the operation in step S11, and thus detailed description thereof is omitted.

Next, preparation for transferring and exposing the pattern formed in the fourth region I ₄ (see FIG. 9) of the pattern region M1 onto the plate P is performed. FIG. 9 is a diagram showing the fourth region I ₄ of the mask M. As shown in FIG. The fourth region I ₄ has a common region I ₄₂ with the second region I ₂ and a common region I ₄₃ with the third region I ₃ . The common area I ₄₂ extending in the X direction is an area that becomes a joint when the pattern formed in the second area I ₂ and the fourth area I ₄ is transferred and exposed on the plate P. ₄₂ a pattern common area I ₂₄ are formed at the second region I ₂ is transferred and exposed superposed on the plate P. Similarly, the common region I ₄₃ extending in the Y direction is a region that becomes a joint when the pattern formed in the third region I ₃ and the fourth region I ₄ is transferred and exposed on the plate P. The pattern formed in the common region I ₄₃ and the common region I ₃₄ of the third region I ₃ is transferred onto the plate P and transferred and exposed.

First, in order to transfer exposure a pattern formed in the fourth region I ₄ on the plate P, as shown in FIG. 9, the common area I ₄₃ extending a first extinction member 9a in the Y-direction + X direction disposed at a position half side is blocked, half of the -Y direction side of the common region I ₄₂ extending a second extinction member 9b in the X direction is arranged at a position where light is blocked. Further, when being scanned and exposed, the common area _{I 42, I} accumulated light amount of _43, the common area _{I 42,} such that the light quantity substantially equal in the region other than the _{I 43,} first dimming member 9a and the second The light reducing member 9b is disposed at a position defocused with respect to the pattern surface of the mask M, that is, at a position separated by a predetermined distance.

Furthermore, in order to transfer exposure a pattern formed in the fourth region I ₄ onto the plate P, and the light shielding so as not to reach the illumination light to illuminate an area other than the fourth region I ₄ on the plate P (step S16). Since the specific operation for light shielding is the same as the operation in step S10, detailed description thereof is omitted.

Next, the mask stage MST is moved to a predetermined position, that is, a scan start position for scanning exposure of the pattern formed in the fourth region I ₄ on the plate P, and formed in the fourth region I _4. The exposed pattern is transferred and exposed on the plate P (step S17). The specific transfer exposure operation is the same as the operation in step S11, and thus detailed description thereof is omitted.

FIG. 10 is a diagram illustrating the state of the plate P when the patterns formed in the first region I ₁ to the fourth region I ₄ are subjected to scanning exposure in steps S14, S17, S20, and S23. Exposure region pattern in R ₁ are formed in the first region I ₁ is transferred and exposed, exposure region pattern formed in the second region I ₂ is transferred and exposed to R _2, the third region in the exposed areas R ₃ the pattern is formed on the I ₃ is transfer exposure, patterns fourth is formed in the region I ₄ is transferred and exposed to an exposure area R _4. As described above, since the screen can be combined and transferred and exposed on the plate P, the size of the mask can be reduced relative to the size of the plate. In addition, since the sizes of the first region I ₁ to the fourth region I ₄ can be freely set, the transfer exposure can be performed by synthesizing a screen (pattern synthesis) according to plates of various sizes.

  Similar to the exposure of the pattern corresponding to the first layer formed in the pattern area M1, the pattern corresponding to the second to fifth layers formed in the pattern areas M2 to M5 and the pattern area M6 The pattern corresponding to the formed first layer is exposed. At this time, switching means for switching at least one of the wavelength and intensity of the illumination light is arranged in the illumination optical system IL, and the wavelength of the illumination light corresponding to the pattern transferred onto the plate P using the switching means before transfer and It is preferable to switch at least one of the strengths. In this case, the pattern can be illuminated with illumination light having a wavelength or intensity suitable for each pattern, and good transfer exposure can be performed.

  According to the mask of this embodiment, even when the mask is deformed (deflection) when mounted on the exposure apparatus, a pattern that requires high exposure accuracy is not easily affected by the deformation of the mask. A pattern that is disposed near the center and does not require high exposure accuracy is disposed nearer to the periphery of the center of the mask that is susceptible to the deformation of the mask. Therefore, each of a pattern that requires high exposure accuracy and a pattern that does not require high exposure accuracy can be satisfactorily exposed on the plate.

  Also, according to the exposure method of this embodiment, since exposure is performed using the mask of the present invention having a pattern corresponding to each layer, it is not necessary to manufacture a mask for each layer of the device, Manufacturing costs can be reduced. Even when the mask is deformed (bent) when the mask is mounted on the exposure apparatus, each of the patterns corresponding to each layer can be satisfactorily exposed on the plate.

  In the mask according to this embodiment, an example in which the size of the pattern areas M1 to M6 is the same is shown. However, for example, a pattern that requires a larger amount of exposure than other patterns is formed. The pattern area to be formed may have a pattern area larger than the pattern area in which another pattern is formed. FIG. 11 is a diagram showing a configuration of another mask M ′. As shown in FIG. 11, the mask M ′ has four pattern areas M11 to M14 having the same size, and a pattern area M15 having a size about twice as large as the pattern areas M11 to M14. An exposure pattern (for example, a gate) corresponding to the first layer of the TFT substrate is formed in the pattern region M11. In the pattern region M12, an exposure pattern (for example, a source / drain and a semiconductor) corresponding to the second layer of the TFT substrate is formed. An exposure pattern (for example, passivation) corresponding to the third layer of the TFT substrate is formed in the pattern region M13. An exposure pattern (for example, a pixel electrode) corresponding to the fourth layer of the TFT substrate is formed in the pattern region M14. In the pattern region M15, an exposure pattern (for example, a black matrix) corresponding to the first layer of the color filter substrate is formed.

  Since an exposure pattern (for example, a black matrix) corresponding to the first layer of the color filter substrate requires a larger exposure amount than other exposure patterns, it is within a pattern area having the same size as the other pattern areas. In the case of forming the film, a longer exposure processing time is required as compared with the exposure processing time of other patterns. Therefore, the substantial exposure processing time is shortened by enlarging the exposure area by making the pattern area larger than the other pattern areas.

  In the mask according to this embodiment, an exposure pattern to be exposed on the TFT substrate and an exposure pattern to be exposed on the color filter substrate are formed, but only the exposure pattern to be exposed on the TFT substrate is formed. Alternatively, only an exposure pattern (for example, black matrix, color filter (R, G, B)) to be exposed on the color filter substrate may be formed.

  In the embodiment as shown in FIG. 11, as an example of the pattern set in the pattern area of about twice the size, the splicing accuracy is higher than that in the other four pattern areas of the same size. Since it is severe, it is effective even in the case of a pattern that reduces the number of times of exposure or splicing once. In this case, a pattern having a desired screen size can be exposed to the pattern region M15 by performing joint exposure in which the other four pattern regions having the same size are joined several times. In this case, it is preferable to arrange the pattern region M15 having a size twice as large as the central portion of the mask. Further, compared to the pattern area M15, the other four pattern areas M11 to M14 having the same size can be individually adjusted for each area, so that adjustment such as overlay with another layer can be easily performed. It is possible to perform the overlay exposure, and it is possible to perform excellent overlay exposure even for partial deformation of the lower layer.

  In the embodiment of the present invention, it can be used as a mask for manufacturing flat panels of various sizes, and device manufacturing can be performed with high accuracy and efficiency.

  In this embodiment, the first dimming member 9a is disposed between the illumination optical system IL and the mask M, but is optically conjugate with the pattern surface of the mask M in the illumination optical system IL. The first dimming member 9a may be arranged at a position away from the position by a predetermined distance.

  Further, in this embodiment, the second dimming member 9b is disposed between the illumination optical system IL and the mask M. For example, as shown in FIG. 12, there is an intermediate between the projection optical units PLa and PLg. Two second dimming members 9b ′ may be provided in the vicinity of the positions where the images 20a and 20g are formed. In addition, 20b-20f shown in FIG. 12 has shown the intermediate image formed in projection optical unit PLb-PLf.

In this embodiment, the patterns formed in the first region I ₁ to the fourth region I ₄ are sequentially scanned and exposed. However, when exposing a multi-faced plate, first, the pattern on the plate is exposed. repeatedly scanning exposing a pattern formed in the first region I ₁ to each area of the then repeated scanning exposure patterns are formed on each of the second region I _{2 ~} fourth region I ₄ on each side You may make it do. That is, it is desirable to perform exposure of each pattern by a method capable of obtaining a high throughput.

  In this embodiment, a so-called multi-lens scanning exposure apparatus has been described as an example. However, the present invention can also be applied to a scanning exposure apparatus that performs exposure using one projection optical system. In this embodiment, a step-and-scan type exposure apparatus that performs scan exposure has been described as an example. However, the present invention is also applied to a step-and-repeat type exposure apparatus that performs batch exposure. can do.

  Further, the use of the exposure apparatus is not limited to an exposure apparatus for liquid crystal that exposes a liquid crystal display element pattern on a square glass plate, for example, for manufacturing an exposure apparatus for semiconductor manufacturing or a thin film magnetic head. It can be widely applied to an exposure apparatus.

In addition, the magnification of the projection optical system PL may be any of an equal magnification system, a reduction system, and an enlargement system. As the projection optical system PL, a material that transmits far ultraviolet rays such as quartz and fluorite is used as a glass material when far ultraviolet rays such as an excimer laser are used, and a catadioptric system or a refractive optical system when an F ₂ laser is used. To.

  In addition, each of the patterns formed in each pattern region may be subjected to enlarged exposure by using the projection optical system PL having an enlargement system magnification. In this case, since the pattern is enlarged and exposed on the plate P, the size of the mask can be made smaller than the size of the plate. Further, screen composition exposure (pattern composition exposure) may be performed while enlarging exposure of the pattern formed in each pattern region by using the projection optical system PL having an enlargement system magnification. Even in this case, since the pattern can be enlarged on the plate P, and the screen can be combined and transferred and exposed, the size of the mask can be made smaller than the size of the plate.

  In the scanning projection exposure apparatus according to the above-described embodiment, a micropattern is obtained by exposing a transfer pattern formed by a reticle (mask) using a projection optical system onto a photosensitive substrate (plate) (exposure process). Devices (semiconductor elements, imaging elements, liquid crystal display elements, thin film magnetic heads, etc.) can be manufactured. Hereinafter, an example of a technique for obtaining a semiconductor device as a micro device by forming a predetermined circuit pattern on a plate or the like as a photosensitive substrate using the scanning projection exposure apparatus according to the above-described embodiment will be described. This will be described with reference to the flowchart of FIG.

  First, in step S301 of FIG. 13, a metal film is deposited on one lot of plates. In the next step S302, a photoresist is applied on the metal film on one lot of plates. Thereafter, in step S303, using the exposure apparatus according to the above-described embodiment, the mask pattern image is sequentially exposed and transferred to each shot area on the plate of the one lot via the projection optical system. Thereafter, in step S304, the photoresist on the one lot of plates is developed, and in step S305, the resist pattern is etched on the one lot of plates to correspond to the mask pattern. A circuit pattern is formed in each shot area on each plate.

  Thereafter, an upper layer circuit pattern is formed, and the plate is cut into a plurality of devices to manufacture devices such as semiconductor elements. According to the semiconductor device manufacturing method described above, since the exposure is performed using the exposure apparatus according to the above-described embodiment, the pattern corresponding to each layer can be satisfactorily exposed while suppressing the cost of the mask, A good semiconductor device can be obtained. In steps S301 to S305, a metal is vapor-deposited on the plate, a resist is applied on the metal film, and exposure, development and etching processes are performed. Prior to these processes, the process is performed on the plate. It is needless to say that after forming a silicon oxide film, a resist may be applied on the silicon oxide film, and steps such as exposure, development, and etching may be performed.

  In the exposure apparatus according to the above-described embodiment, a liquid crystal display element as a micro device can be obtained by forming a predetermined pattern (circuit pattern, electrode pattern, etc.) on a plate (glass substrate). Hereinafter, an example of the technique at this time will be described with reference to the flowchart of FIG. First, in FIG. 14, in a pattern forming step S401, a so-called photolithography step is performed in which the exposure pattern according to the above-described embodiment is used to transfer and expose a mask pattern onto a photosensitive substrate (such as a glass substrate coated with a resist). Is executed. By this photolithography process, a predetermined pattern including a large number of electrodes and the like is formed on the photosensitive substrate. Thereafter, the exposed substrate undergoes steps such as a developing step, an etching step, and a resist stripping step, whereby a predetermined pattern is formed on the substrate, and the process proceeds to the next color filter forming step S402.

  Next, in the color filter forming step S402, a large number of groups of three dots corresponding to R (Red), G (Green), and B (Blue) are arranged in a matrix or three of R, G, and B A color filter is formed by arranging a plurality of stripe filter sets in the horizontal scanning line direction. Then, after the color filter formation step S402, a cell assembly step S403 is executed. In the cell assembly step S403, a liquid crystal panel (liquid crystal cell) is assembled using the substrate having the predetermined pattern obtained in the pattern formation step S401, the color filter obtained in the color filter formation step S402, and the like. In the cell assembly step S403, for example, liquid crystal is injected between the substrate having the predetermined pattern obtained in the pattern formation step S401 and the color filter obtained in the color filter formation step S402, and a liquid crystal panel (liquid crystal cell ).

  Thereafter, in a module assembly step S404, components such as an electric circuit and a backlight for performing a display operation of the assembled liquid crystal panel (liquid crystal cell) are attached to complete a liquid crystal display element. According to the above-described method for manufacturing a liquid crystal display element, since exposure is performed using the exposure apparatus according to the above-described embodiment, a pattern corresponding to each layer can be satisfactorily exposed, and a good liquid crystal display An element can be obtained.

It is a figure which shows the structure of the exposure apparatus concerning embodiment. It is a figure which shows the structure of the mask concerning embodiment. It is a figure which shows the deformation | transformation of a mask. It is a figure which shows the structure of the mask stage concerning embodiment. It is a flowchart for demonstrating the exposure method concerning embodiment. It is a figure for demonstrating a 1st area | region. It is a figure for demonstrating a 2nd area | region. It is a figure for demonstrating a 3rd area | region. It is a figure for demonstrating a 4th area | region. It is a figure which shows the state of the plate when the pattern currently formed in the 1st area | region-the 4th area | region was scanned and exposed. It is a figure which shows the structure of another mask. It is a figure which shows the structure of another 2nd light attenuation member. It is a flowchart which shows the manufacturing method of the semiconductor device as a microdevice concerning embodiment of this invention. It is a flowchart which shows the manufacturing method of the liquid crystal display element as a microdevice concerning embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... Elliptic mirror, 3 ... Dichroic mirror, 4 ... Relay optical system, 5 ... Light guide, 6a-6g ... Illumination optical unit, 9a ... 1st light reduction member, 9b ... 2nd light reduction member, 9c ... light-shielding member, 10a, 10b ... guide part, 15 ... autofocus detection system, IL ... illumination optical system, PL ... projection optical system, PLa to PLg ... projection optical unit, M ... mask, MST ... mask stage, P ... plate .

Claims (18)

In a mask including at least a first pattern and a second pattern exposed on a substrate,
Placing the first pattern, which requires higher exposure accuracy than the second pattern, in the vicinity of the center of the mask;
The mask, wherein the second pattern is arranged at a periphery of the center portion of the mask.   The mask according to claim 1, wherein the first pattern has a minimum pattern line width narrower than that of the second pattern.   The mask according to claim 1, wherein the first pattern is required to have a higher pattern position accuracy than the second pattern.   4. The mask according to claim 1, wherein the first pattern and the second pattern are patterns corresponding to different layers on the substrate. 5. The substrate is a substrate for a display element,
The mask according to any one of claims 1 to 4, wherein the first pattern includes a pixel pattern of the display element. The substrate is a substrate for a display element,
The mask according to any one of claims 1 to 5, wherein the second pattern is at least one of a color filter pattern and a black matrix pattern of the display element.   When exposing the first pattern or the second pattern, the first pattern and the second pattern are arranged based on deformation of the mask caused by holding the mask. The mask according to any one of claims 1 to 6. Using a mask including at least a first pattern and a second pattern exposed to different layers on the substrate;
An exposure method characterized in that each of the exposure of the first pattern and the second pattern performs at least one of expansion exposure and pattern synthesis exposure.   The first pattern, which is required to have higher exposure accuracy than the second pattern, is arranged near the center of the mask, and the second pattern is arranged around the center of the mask. The exposure method according to claim 8, which is used specially.   The exposure method according to claim 9, wherein the exposure accuracy includes a pattern width of the first pattern and a minimum pattern line width of the second pattern or a pattern position accuracy during exposure.   When exposing the first pattern or the second pattern, the first pattern and the second pattern are arranged based on deformation of the mask caused by holding the mask. The exposure method according to any one of claims 8 to 10. The substrate is a substrate for forming a display element,
The exposure method according to any one of claims 8 to 11, wherein the first pattern includes a pixel pattern of the display element. The mask has a third pattern exposed to a second substrate different from the substrate;
13. The third pattern according to claim 8, wherein the third pattern is formed such that the pattern surface of the substrate and the pattern surface of the second substrate are combined to face each other. The exposure method as described. The substrate is a substrate for forming a display element,
14. The exposure method according to claim 8, wherein the second pattern is at least one of a color filter pattern and a black matrix pattern of a display element. The substrate is a substrate for forming a display element,
14. The exposure method according to claim 8, wherein the third pattern is at least one of a color filter pattern and a black matrix pattern of a display element.   16. At least one of the first pattern and the second pattern is projected and exposed on the substrate via a plurality of projection optical systems. The exposure method according to item.   The exposure method according to claim 8, wherein the substrate is a photosensitive substrate having an outer diameter larger than 500 mm. An exposure step of exposing a predetermined pattern on a substrate by the exposure method according to any one of claims 8 to 17,
A development step of developing the substrate exposed by the exposure step;
A method for manufacturing a display element, comprising:

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